Plant Cells and Tissues

Plant Cells and Tissues

• Plant tissues are groups of cells that work together for structure and function.
• Tissues form systems in plants.
• There are three tissue systems: ground, vascular, and dermal.

Ground Tissue System

• Parenchyma cells:
  • Unspecialized plant cells.
  • Thin walls.
  • May contain chlorophyll.
  • Loosely packed.
  • Functions: photosynthesis, storage, secretion.
• Collenchyma cells:
  • Living plant cells.
  • Unevenly thickened primary walls.
  • Provide support in soft, non-woody plant parts.
• Sclerenchyma cells:
  • Plant cells with extremely thick walls, providing strength and support to the plant body.
  • Two types:
    • Sclereids: found in shells of nuts, stones of fruits, pears.
    • Fibers: found in wood, inner bark, and leaf ribs.

Vascular Tissue System

• Xylem:
  • Transports water and dissolved minerals throughout the plant.
  • Tracheids and vessel elements conduct water and minerals.
  • Parenchyma cells are for storage.
  • Fibers provide support.
• Phloem:
  • Transports food (sugars) throughout the plant body.
  • Sieve tube elements are long, thin cells stacked end-to-end forming sieve tubes.
  • Sieve plates are end walls with holes for cytoplasm to connect cells.
  • Companion cells are adjacent to sieve tube elements; assist in functions of sieve tube elements.

Dermal Tissue System

• Epidermis:
  • Outermost layer (usually one cell thick).
  • Covers the plant body.
  • Cuticle is secreted on stems and leaves to reduce water loss.
  • Stomata facilitate carbon dioxide diffusion during photosynthesis.

Meristems

• Apical meristems:
  • Located at tips of stems and roots.
  • Produce primary tissues (responsible for plant's primary growth — increasing length).
• Lateral meristems:
  • Located on the side of the vascular plant.
  • Vascular cambium and cork cambium give rise to secondary tissues (responsible for secondary growth, widening the plant).

Periderm

• Outermost layer of cells.
• Covers woody stems and roots.
• Consists of cork cells (dead at maturity).
• Coated with suberin (a waxy substance).
• Cork parenchyma (phelloderm) is for storage.

Explore the fascinating world of plant cells and their tissue systems. This quiz covers the three primary types of plant tissues: ground, vascular, and dermal, along with the functions and characteristics of various cell types. Test your knowledge on how these tissues contribute to plant structure and function.